diff --git a/ament_cmake_libraries/CMakeLists.txt b/ament_cmake_libraries/CMakeLists.txt
index 20092c42..3d5b8675 100644
--- a/ament_cmake_libraries/CMakeLists.txt
+++ b/ament_cmake_libraries/CMakeLists.txt
@@ -8,6 +8,11 @@ ament_package(
   CONFIG_EXTRAS "ament_cmake_libraries-extras.cmake"
 )
 
+include(CTest)
+if(BUILD_TESTING)
+  add_subdirectory(test)
+endif()
+
 install(
   DIRECTORY cmake
   DESTINATION share/${PROJECT_NAME}
diff --git a/ament_cmake_libraries/test/CMakeLists.txt b/ament_cmake_libraries/test/CMakeLists.txt
new file mode 100644
index 00000000..e84ab5e1
--- /dev/null
+++ b/ament_cmake_libraries/test/CMakeLists.txt
@@ -0,0 +1 @@
+add_test(deduplicate "${CMAKE_COMMAND}" -P ${CMAKE_CURRENT_LIST_DIR}/test_deduplicate.cmake)
diff --git a/ament_cmake_libraries/test/test_deduplicate.cmake b/ament_cmake_libraries/test/test_deduplicate.cmake
new file mode 100644
index 00000000..23cd4cd1
--- /dev/null
+++ b/ament_cmake_libraries/test/test_deduplicate.cmake
@@ -0,0 +1,31 @@
+include("${CMAKE_CURRENT_LIST_DIR}/utilities.cmake")
+
+# Empty
+set(TEST_IN "")
+ament_libraries_deduplicate(ACTUAL ${TEST_IN})
+assert_equal("" "${ACTUAL}")
+
+# Noop
+set(TEST_IN "foo;bar;baz")
+ament_libraries_deduplicate(ACTUAL ${TEST_IN})
+assert_equal("foo;bar;baz" "${ACTUAL}")
+
+# Simple
+set(TEST_IN "foo;bar;baz;bar")
+ament_libraries_deduplicate(ACTUAL ${TEST_IN})
+assert_equal("foo;baz;bar" "${ACTUAL}")
+
+# With matching build configs
+set(TEST_IN "debug;foo;debug;bar;debug;baz;debug;bar")
+ament_libraries_deduplicate(ACTUAL ${TEST_IN})
+assert_equal("debug;foo;debug;baz;debug;bar" "${ACTUAL}")
+
+# With missing build configs
+set(TEST_IN "debug;foo;debug;bar;debug;baz;bar")
+ament_libraries_deduplicate(ACTUAL ${TEST_IN})
+assert_equal("debug;foo;debug;bar;debug;baz;bar" "${ACTUAL}")
+
+# With mismatched build configs
+set(TEST_IN "debug;foo;debug;bar;debug;baz;release;bar")
+ament_libraries_deduplicate(ACTUAL ${TEST_IN})
+assert_equal("debug;foo;debug;bar;debug;baz;release;bar" "${ACTUAL}")
diff --git a/ament_cmake_libraries/test/utilities.cmake b/ament_cmake_libraries/test/utilities.cmake
new file mode 100644
index 00000000..8bef757f
--- /dev/null
+++ b/ament_cmake_libraries/test/utilities.cmake
@@ -0,0 +1,8 @@
+set(ament_cmake_libraries_DIR "${CMAKE_CURRENT_LIST_DIR}/../cmake")
+include("${CMAKE_CURRENT_LIST_DIR}/../ament_cmake_libraries-extras.cmake")
+
+macro(assert_equal EXPECTED ACTUAL)
+  if(NOT "${EXPECTED}" STREQUAL "${ACTUAL}")
+    message(SEND_ERROR "Assert failed: Expected '${EXPECTED}', got '${ACTUAL}'")
+  endif()
+endmacro()